1. Field
The following description relates to a frequency control technique for matching a frequency from a transmitting party to a frequency from a receiving party, and more particularly, to an automatic frequency control apparatus for automatically correcting a frequency error due to sharp changes in frequency generated when a mobile terminal moves quickly.
2. Description of the Related Art
Recently, many mobile communication techniques adopt an Orthogonal Frequency Division Multiple Access (OFDMA) scheme or a Single-Carrier FDMA (SC-FDMA) scheme. IEEE 802.16, 802.20 that is a standard for mobile internet system and a standard for Wibro system adopt the OFDMA scheme, and 3 Generation Partnership Project (3GPP) adopts use of the OFDMA and SC-FDMA schemes in a cellular communication system called Long Term Evolution (LTE).
However, communication methods based on the OFDMA or SC-FDMA scheme could not avoid performance deterioration due to noise since noise is generated in all transmission packets when a RF center frequency from a transmitting party does not accurately match that from a receiving party.
In order to solve such a performance deterioration problem, generally, a technique of measuring channel distortion by transmitting a reference signal to a predetermined resource space (that is, at a predetermined frequency and a predetermined time) to compensate for the channel distortion, thereby removing noise over entire data has been used.